Guest Post by Mae Smith, University of Wyoming Extension Educator, Big Horn County

In goes garbage, out comes black gold. Vermicomposting (composting using worms) is a great way to recycle food waste into a product that will help ensure a bumper vegetable crop.

Want to build your own worm bin? Here is what you will need:

Container

Bedding

Water

Worms

Non-fatty kitchen scraps

ContainerContainers can be purchased or built. Plastic storage containers are light, convenient, and come in a variety of sizes. Wooden bins can be more durable and provide better air movement. Surface area is more important than the type of material. Containers 1-foot deep or less work best. They are more efficient and have less potential odor problems than those that are deeper. Depending on the size, the bin can be kept in the house, in a heated garage, or outside depending upon the temperature and available space.

Holes (1/4 – ½ inches) drilled in the sides and bottom of the bin allow air movement while keeping the bin dark. More holes are needed in a plastic container than one made of wood because wood naturally breathes.

The bin should be raised on bricks or blocks with a tray underneath to catch the “worm tea” (the juices that are secreted). This worm tea is packed full of nutrients and can be used as liquid plant fertilizer.

Building a worm bin at the 2016 WESTI Ag Days in Worland

BeddingOnce you have your bin ready, the next step is bedding. Here are some materials that make great bedding:

Shredded newspaper – the ink is not a problem but the bleach used in computer paper is not desirable

WormsObtain the worms through lawn and garden catalogs, websites, bait stores, or harvest them from a friend’s worm bin when their worms are stampeding. Place the worms in the bin (and while you are at it, check out this AMAZING worm video).

The best worms to use are commercially grown red worms (Lumbricus rubellus or Eisenia foetida). Common garden worms do not do well in home composting systems. Red worms grow best in temperatures between 55 and 77 F. The bedding temperature should not dip below freezing or exceed 84 F.

WaterThe bedding should be moistened before the worms arrive and maintained at a moisture level similar to that of a wrung-out sponge.

Non-fatty Kitchen ScrapsTips for feeding worms:

Start adding food slowly so helpful bacteria can build up in the bin. Worms may not eat the garbage right away.

Worms have gizzards like chickens, so they need fine, gritty material such as coffee grounds, cornmeal, or soil.

Worms don’t need fed every day; once or twice a week is fine. They won’t starve because they will eat bedding, too.

Place scraps in one area of the bin and cover with a layer of bedding (reduces odor and pests). Rotate where you add the scraps. The worms will migrate to the new food when they are ready.

Worm food

Harvesting Your TreasuresAfter feeding the worms three to four months, they have probably eaten most of your “trash” and turned it into “treasure.” At this point, you may want to start harvesting the compost (or you can wait longer but add moist bedding if needed and eventually, the bin will get full.)You can either:

Move the material to one side and add fresh bedding to the other side. Feed the worms in the new bedding and wait a couple of days for them to migrate. Scoop out the finished compost making sure you leave worms and their eggs (small, opaque cocoons) in the bin.

Shine a bright light on the surface so the worms migrate to the lower layers. Harvest the top layers watching for worms and eggs. Replenish the bedding and food.

Use this rich, black natural fertilizer on potted plants or work it into your garden soil. It is packed with nutrients but mild enough you don’t have to worry about burning or over fertilizing.

Food scraps and bedding have been added to the right side of this worm binand worm castings can be harvested from the left side